Dynamics of dense laser-induced plasmas

Yoffa, Ellen J.

doi:10.1103/physrevb.21.2415

Cited by 280 publications

(76 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The average absorbed laser energy density is a function of excitation fluence and probe depth. This model is consistent with the expected fast electronic equilibration [24] and compara- tively slow rate of phonon emission [21] and ambipolar diffusion in a dense plasma [25]. In order to compare disordering time scales, the time required for the diffraction intensity to drop to 1=e of its original value ( 1=e ) is used.…”

Section: Institut Für Experimentelle Physik Universität Duisberg-essmentioning

confidence: 63%

Carrier-Density-Dependent Lattice Stability in InSb

et al. 2007

View full text Add to dashboard Cite

The ultrafast decay of the x-ray diffraction intensity following laser excitation of an InSb crystal has been utilized to observe carrier dependent changes in the potential energy surface. For the first time, an abrupt carrier dependent onset for potential energy surface softening and the appearance of accelerated atomic disordering for a very high average carrier density have been observed. Inertial dynamics dominate the early stages of crystal disordering for a wide range of carrier densities between the onset of crystal softening and the appearance of accelerated atomic disordering. DOI: 10.1103/PhysRevLett.98.125501 PACS numbers: 63.20.Kr, 61.10.ÿi, 64.70.Dv, 78.47.+p First-order phase transitions and chemical reactions require crossing a transition state on the potential energy surface (PES). Characterizing the topography of the energy landscape in the vicinity of the transition state represents the key step to understanding the pathway followed during a chemical reaction or first-order phase transition. The experimental and theoretical characterization of these far from equilibrium regions of the PES has proven to be very difficult because of the vanishingly short time spent near the transition state and the multitude of degrees of freedom that influence chemical and physical transformations in the condensed phase. Time-resolved x-ray scattering experiments provide a window for observing the structural dynamics that occur during certain physical transformations. This is achieved by using femtosecond (fs) x-ray pulses to monitor laser initiated dynamics, selectively track the time-dependent evolution of nonequilibrium atomic structures, and extract the shape of a photoinduced PES [1][2][3][4].This approach has proven crucial to investigating the influence of carrier excitation on the stability of tetrahedrally bonded semiconductors. Theoretical, experimental, and simulation studies of these systems indicate that extreme carrier densities destabilize the crystal structure and lead to nonthermal melting [3,[5][6][7][8][9][10][11][12][13][14][15][16][17]. Theoretical studies predict a rapid reduction in the shear restoring force when the excited carrier density exceeds a few percent of the valence band electron density [5][6][7]. A further doubling of the carrier density eliminates the shear restoring force, transforms the room temperature potential energy minimum into a saddle point, and leads to accelerated atomic disordering.The initial ultrafast x-ray diffraction studies of laserexcited InSb at the Sub-Picosecond Pulse Source (SPPS) determined that inertial atomic displacements on a lasersoftened potential energy surface dominate the response to intense optical excitation during the first 500 fs for a range of laser fluences [3]. This predominance of inertial dynamics in a wide fluence range had not been predicted by either theory or simulation. While the studies of Lindenberg et al. [3] and Gaffney et al. [15] covered the mean carrier density range over which theory predicted crystal stability to r...

show abstract

Section: Institut Für Experimentelle Physik Universität Duisberg-essmentioning

confidence: 63%

Carrier-Density-Dependent Lattice Stability in InSb

et al. 2007

View full text Add to dashboard Cite

show abstract

“…The fullest analyses of the non-radiative transitions are those of Yoffa (1980) and Dumke (1980). Both note that Auger recombination is fast at high carrier densities.…”

Section: Laser Annealingmentioning

confidence: 99%

Non-radiative transitions in semiconductors

1981

View full text Add to dashboard Cite

Non-radiative transitions affect many aspects of semiconductor performance. Normally they reduce device efficiency by suppressing luminescence, creating defects, reducing carrier lifetimes, or enhancing diffusion during operation. The present review surveys both the theoretical and practical understanding of non-radiative transitions. It includes general theoretical results and the associated ideas, with the emphasis on phonon-induced and defect Auger processes. Most of the purely formal aspects are omitted, but the points of principle where uncertainties remain are discussed. The review also covers the relation between basic theoretical studies and practical applied work on device degradation. This includes a description of the atomic processes involved in the more important mechanism of device deterioration and the theoretical understanding of the mechanism of these underlying processes. Finally, there is a survey of models proposed for 'killer' centres.

show abstract

“…22,23 The dynamics of nanosecond-laser heating and the melting threshold are usually described within the frames of the thermal model based on the heat-flow equation. 24,25 At shorter laser pulses, the electron and lattice subsystems are treated separately, involving ambipolar diffusion [26][27][28][29] or drift-diffusion 14,30,31 approaches. By using a drift-diffusion formalism, it has been demonstrated that the macroscopic Coulomb explosion in silicon is improbable at femtosecond, IR laser irradiation, 30 while the conditions for electrostatic disintegration of the external layer of the silicon targets can be created at longer, nanosecond UV pulses 31,32 with fluences below the melting threshold.…”

Section: Introductionmentioning

confidence: 99%

Insight into electronic mechanisms of nanosecond-laser ablation of silicon

Marine

Bulgakova

Patrone

et al. 2008

Journal of Applied Physics

View full text Add to dashboard Cite

To cite this version:Wladimir Marine, N.M. Bulgakova, Lionel Patrone, Igor Ozerov. Insight into electronic mechanisms of nanosecond-laser ablation of silicon. We present experimental and theoretical studies of nanosecond ArF excimer laser desorption and ablation of silicon with insight into material removal mechanisms. The experimental studies involve a comprehensive analysis of the laser-induced plume dynamics and measurements of the charge gained by the target during irradiation time. At low laser fluences, well below the melting threshold, high-energy ions with a narrow energy distribution are observed. When the fluence is increased, a thermal component of the plume is formed superimposing on the nonthermal ions, which are still abundant. The origin of these ions is discussed on the basis of two modeling approaches, thermal and electronic, and we analyze the dynamics of silicon target excitation, heating, melting, and ablation. An electronic model is developed that provides insight into the charge-carrier transport in the target. We demonstrate that, contrary to a commonly accepted opinion, a complete thermalization between the electron and lattice subsystems is not reached during the nanosecond-laser pulse action. Moreover, the charging effects can retard the melting process and have an effect on the overall target behavior and laser-induced plume dynamics.

show abstract

Dynamics of dense laser-induced plasmas

Cited by 280 publications

References 34 publications

Carrier-Density-Dependent Lattice Stability in InSb

Carrier-Density-Dependent Lattice Stability in InSb

Non-radiative transitions in semiconductors

Insight into electronic mechanisms of nanosecond-laser ablation of silicon

Contact Info

Product

Resources

About